JP2807301B2 - Method for preparing ferroelectric liquid crystal Si-containing polymer and its use in electro-optical members - Google Patents

Abstract

Ferroelectric liquid-crystal polymers containing Si and corresponding to formula (I), where z = CH3? or a group according to formula (II): (CH2?)a?(-B)b?-M?1(-A?1)c?(-M?2)d?(-A?2)e?(-M?3)f?(-A?3)g?-R?1, provided that at least two z substitutes in the polymer are a group according to formula (II); n = 5 to 500; B = for example a group of formula (III); A?1, A?2, A?3 = for example pyrimidin-2,5-diyl; M?2, M?3 = for example CO-O or O-CO; M?1 = O, CH2?-CH2?, O-CO or COO; R?1 = for example alkyl with 1 to 16 atoms of C; a = 2 to 20; b, c, d, e, f, g = 0 or 1, and G = for example alkylene with 1 to 16 atoms of C. Said polymers are suitable for use in electro-optical elements because of their short switching times.

Description

DETAILED DESCRIPTION OF THE INVENTION Liquid crystals have recently been developed to provide certain electro-optical properties (eg, low addressing voltage) in addition to certain required properties (eg, flat structure, low weight) for display or switching devices. voltage)) have been introduced in various industrial fields. These devices are generally based on a dielectric alignment effect that affects the nematic, cholesteric and / or smectic liquid crystal phases, and the light transmittance or reflectivity of the device depends on the applied voltage.

Liquid crystal displays comprise two support plates, preferably two glass plates coated with transparent electrodes, typically in a uniaxial or biaxial orientation, between which a liquid crystal layer is arranged. Other members include a polarizer,
Color filters, protective coatings, anti-reflective coatings, anti-diffusion coatings and the like are common.

Even today, nematic or smectic liquid crystal phases are used as the main liquid crystals, but in recent years the importance of smectic C ^* liquid crystal phases in particular has increased.
Ferroelectric liquid crystals have the advantage of short switching times, and are required when using nematic or cholesteric liquid crystal phases, without the need for electrical elements such as thin-film transistors, for example, for high-resolution display screens. It makes the operation easier.

For all of the above applications, low molecular weight liquid crystal compounds, i.e., 20
Compounds having a molecular weight of less than 00 g / mol, preferably less than 800 g / ml were required, especially compounds that are not polymers, copolymers, polycondensates or copolycondensates. Because of low viscosity,
In general, low molecular weight liquid crystals have the advantage of short switching times; this is especially true for switching times in the microsecond range, which are 10-1000 times higher than for conventional nematic liquid crystal phases.
This applies to ferroelectric liquid crystals that switch twice as fast.

However, when using ferroelectric liquid crystals, the problem arises that the orientation is very sensitive with respect to mechanical loads (vigorous shaking, shock, pressure, thermal deformation, bending, etc.), thereby irreversibly affecting the image quality of the display. May cause serious damage. In general, this high sensitivity makes the construction of soft ferroelectric LC displays more difficult, and also increases the cost of manufacturing conventional displays, ie, displays compatible with glass or hard plastic plates.

Due to their low deformability and better sensitivity, it is advantageous to use polymer liquid crystals; they can be used to produce soft ferroelectric displays. In order to obtain a polymer ferroelectric liquid crystal having a fast switch, it is particularly convenient to manufacture a display film by a continuous method. Accordingly, the present invention relates to the preparation of new polymer ferroelectric liquid crystals.

The new compound (as is) has the following formula (I): [Wherein z is CH ₃ or formula (II) (CH ₂ ) _a (-B) _b -M ¹ , provided that at least two substituents z in the polymer are groups of formula (II). (−A ¹ ) _c (−M ² ) _d (−A ² ) _e (−M ³ ) _f (−
A ³ ) a group represented by _g- R ¹ (II), n is 5 to 500, and B is a group represented by the following formula: (Wherein R ⁶ , R ⁷ and R ⁸ are the same or different and H, CH ₃ , OC
H ₃ , F, Cl or Br, in which case at least one group
R ⁶ , R ⁷ , or R ⁸ must be H. Next, X is H, F, Cl
Or R ⁹ is H or a C ₁ -C ₁₀ alkyl), and R ¹ is one or two non-adjacent —CH ₂
Groups represented by -O-, -S-, -CO-, -CO-O-, -O-CO
Straight or branched having 1 to 16 carbon atoms (having an asymmetric carbon atom, or which can be replaced by -O-CO-O- and also H can be replaced by F; or Alkyl) or alkenyl having 2 to 16 carbon papers, or also the following radicals (Wherein R ² , R ³ , R ⁴ and R ⁵ are H, or one —CH ₂ — group can be substituted by —O—, —C—O—O—, or —O—CO—. Possible straight or branched alkyl having 1 to 16 carbon atoms, or alkenyl having 2 to 16 carbon atoms, or R ² and R ³ or R ³ and R ⁴ are the same, or A) is a cyclic alkyl having 3 to 8 carbon atoms), a is 2 to 20, preferably 6 to 12, and b, c, d, e, f and g are e + f + g is 2
Or 0 or 1 under the condition that they are 3, and A ¹ , A ²
And A ³ are the same or different and 1,4-phenylene in which one or two H can be replaced by F, Cl, and / or CN, and one or two H can be replaced by F, Cl, CN and / or or trans-1,4-cyclohexylene which may be substituted by CH _3, pyrazine-2,5-diyl, pyridazine-3,6-diyl, pyridine-2,5-diyl, pyrimidine-2,5-diyl, (1,3,4) -thiadiazole-2,5-diyl, 1,3-
A dioxane-2,5-diyl or 1,3-dithiane-2,5-diyl, M ² and M ³ are identical or different CO-O, O-CO, CO-
S, S-CO, a CH ₂ -O or O-CH _2, M ¹ is Or CH ₂ —CH ₂ , and G represents one or two non-adjacent —CH ₂ groups by —O—, —S—, —O—CO, —CO—O—,
Linear or branched alkyl having 1 to 16 carbon atoms, or alkenyl having 2 to 16 carbon atoms, which can be substituted by -S-CO- or -CO-S-. .

Preferred ferroelectric liquid crystalline polymer of the formula (I), groups _{^{(-A 1) c (M 2}} ) d (-A 2) e (-M 3) f (-A 3) g -
But: Is the polymer.

Particularly preferred ferroelectric liquid crystalline polymers of formula (I) are:
B is as defined in claim 1, Y is H or CH _3, the R ¹ is one or two non-adjacent -CH ₂ groups, -
O-, -S-, -CO-, -CO-O-, -O-CO- or-
Can be replaced by O-CO-O- and also H is F or radical Linear or branched (with or without asymmetric carbon atoms) alkyl or alkenyl having 2 to 16 carbon atoms, wherein a is 6 to
At 12, the group (-A ¹ ) _c (-M ² ) _d (-A ² ) _e (-M ³ )
_f (-A ³⁾ _g - is the following structure: Is a polymer having the formula:

Similarly, particularly preferred ferroelectric liquid crystalline polymers of formula (I) are those in which each z is a group of formula (II).

The above-mentioned Si-containing polymer has the general formula (III) CH ₂ CHCH (-CH ₂ ) _a-2 (-B) _b -M ¹ (-A ¹ ) _c (-M ² ) _d (-A ² ) _e (-
M ³ ) _f (-A ³ ) _g -R ¹ (III) and a compound of formula (IV) Wherein n is from 5 to 500 and y is H or CH ₃ , provided that at least two y groups are H.

The Si-containing polymers of the present invention are particularly suited for use in electro-optical components.

During General Procedure pure CH ₂ Cl ₂ 10 ml for esterification with EXAMPLE 1 A) General Procedure (I) dicyclohexylcarbodiimide, in a suitable alcohol 1 mmol, 4
-15 mol% of dimethylaminopyridine (DMAP) and 1 mmol of carboxylic acid were added while stirring to remove water. The mixture is cooled to 0 ° C. and dicyclohexylcarbodiimide (sic) (DCC) is added. The mixture is then stirred for 30 minutes at 0 ° C. and 18 hours at room temperature. The precipitated material is filtered off, the CH ₂ Cl ₂ phase is washed with water and MgSO
Dry using ₄ to remove the solvent.

(II) Tetrahydropyranyl ether (THP ether)
General procedure for cleaving 5 mmol of THP ether and 0.5 mmol of PPTS (pyridinium-p-toluenesulfonate) in 40 ml of ethanol
Stir at 3 ° C (oil bath temperature) for 3 hours. The solvent was removed, washed the residue with H ₂ O.

(III) Terminal alkene and polyhydrogen methylsiloxane (PHM
General procedure for the addition reaction of S) Weigh 1.1 mol of the appropriate alkene into a 100 ml three-necked flask. Next, 40 ml of toluene heated with LiAlH ₄ are distilled into the flask. After the mixture has cooled, 1 mmol of freshly recrystallized PHMS SiH is added. The reaction mixture is N
Flush with ₂ and heat to boiling while removing water. Then, pure isopropanol, H ₂ PtCl ₂ · 6
Inject H ₂ O 10 ^-4 mmol and stir the mixture at 100 ° C. for 40 h. After cooling the reaction mixture, add 70 ml of MeOH dropwise with vigorous stirring.
The product precipitated. The polymer is filtered off, dissolved in 30 ml of toluene, recrystallized eight times and dried in vacuo.

B) Preparation of monomer of the formula 4-butoxyphenyl 4-tetrahydropyran-2-yloxybenzoate (3) According to the general procedure (I), (2) 7 g (32 mmol)
5.23 g (38 mmol) of 4-butoxyphenol, 0.7 g of DMAP,
And 6.5 g (38 mmol) of DCC are added. The crude product was purified by column chromatography (eluent CH ₂ Cl _2).
A white oil is isolated. Yield: 8.36 g (72%).

4-butoxyphenyl 4-hydroxybenzoate (4) According to general procedure (II), in 180 ml of ethanol,
(3) To 8.36 g (23 mmol), add 573 mg (2.3 mmol) of PPTS and stir the mixture at 55 ° C. (oil bath temperature) for 6 hours. The ethanol was removed by distillation, ether was added to the residue, the solution after washed with H ₂ O, the solvent is removed by drying over MgSO _4.

Yield: 6.08 g (93%), mp: 153 ° C.

Methyl (R)-(+)-6-hydroxy-3-methylhexarate (10) 9.42 g (51 mmol) of (R)-(+)-methylcitronellate (9) in 26 ml of methanol (same as text) And saturate the solution with 2.45 g (51 mmol) of O _{3 at} −30 ° C. for 1 hour. Next, while stirring, 3.12 g of NaBH ₄
(82 mmol) are added in small portions. During the highly exothermic reaction lasting 2 hours, the temperature is kept between -20 ° C and + 10 ° C. Thereafter, the cooling is stopped and the temperature of the mixture is raised to room temperature. A large amount of methanol is removed by distillation and 80 ml of CHCl ₃ are added to the residue. At 0 ° C., the mixture is added while stirring vigorously a solution of 100 g of ice and 50 ml of concentrated HCl. The chloroform phase is washed once with Na ₂ CO ₃ and three times with H ₂ O. Then dry with MgSO ₄ and evaporate. The crude product is distilled in a valve tube. Yield: 5.12 g (68%), [[α] ²⁰ _D ▼ = +9.3 ゜ (C = 1 in chloroform), boiling point: 85 ° C.

Dehydration Tosylate (1 mmol) prepared as follows
In 0 ml, add (Bn ₄ N) ₂ (CO ₂ ⁻ ) ₂ . The mixture is heated at 160 ° C. for 2 hours. After the mixture has cooled, it is treated with water, the product is extracted with ether and distilled.

(3R) -3-methylhexenoic acid (5) According to general procedure (I), (11) 2.5 g (10 mmol)
At 80 ° C. with 1.15 g (20 mmol) of KOH in 20 ml of ethanol.
And stir for 3 hours. A clear reaction mixture is liberated from the ethanol in vacuo. Add ice water and add ether layer. At 0 ° C, stir vigorously
20 ml of 1N HCl are added dropwise to this mixture. The organic phase was separated washed with H ₂ O, evaporated and dried over MgSO _4. The viscous residue is reacted without further purification.

(3R) -3-Methylhexenoyloxy 4-butoxyphenylbenzoate (6) According to general procedure (I), (4) 2.6 g (9.1 mmol)
(5) 2.09 g (9.1 mmol), DMAP 167 mg, and DCC 1.87
g (9.1 mmol). Purification is performed by column chromatography (eluent E / PE 1: 1). A colorless oily liquid is isolated. Yield: 3.01 g (67%).

See general procedure for addition reaction with siloxane.

Example 2 According to the method of Meyer et al. In JACS 98 , p.567 (1976), (1S, 2S)-(+)-1-phenyl-2-amino-1,3-propanediol and the formula CH ₃ CH ₂ C (OC ₂ H ₅ ) ₃
Reacting the orthoester of the formula An oxazoline compound of formula Next, the obtained oxazoline compound is represented by the following formula: With hydride / sodium methyl iodide. Further, the obtained compound is
Metallization using LDA, at -98 ° C., the formula H ₂ C = CH (−
CH ₂ ) ₂ -I. Was obtained in a yield of 25%.

2.13 g of this compound was refluxed with 4NH ₂ SO ₄ for 3.5 hours.
After reflux, 1.16 g of the compound was obtained.

This acid is converted to the following formula in CH ₂ Cl ₂ in the presence of dicyclohexylcarbodiimide: Esterification with the compound of the formula Was obtained in a yield of 83%.

See general procedure for addition reaction with siloxane.

Example 3 Synthesis Examples for

9-decenyl 4-toluenesulfonate (A) 10 g of 9-decenol in 80 ml of pure CHCl ₃ without water
(70 mmol) and 14.7 g of 4-toluenesulfonyl chloride (7
7 mmol), 10 ml (140 mmol) of pyridine are added dropwise. At 0 ° C., stir the mixture for 30 minutes and then at room temperature for 20 hours. The reaction mixture was acidified using cold dilute HCl solution; the CHCl ₃ phase was separated, washed with H ₂ O until neutral and dried over MgSO ₄ to remove solvent; yield 16.9 g ( 78%).

Methyl 4- (9-decenyloxy) benzoate (B) A15.8 g (50 mmol), methyl 4-hydroxybenzoate 7.6 g (50 mmol), and K ₂ CO ₃ 6.9 g in 100 ml of acetone
The solution is refluxed for 24 hours. 100 ml of CH ₂ Cl _{2 in the} cooled mixture
And extract twice with 0.1N NaOH aqueous solution. Dry the organic phase over MgSO ₄ and remove the solvent; yield 10.6 g
(73%).

Dissolve 10.0 g (34.5 mmol) of 4- (9-decenyloxy) benzoic acid (C) B in ethanol and 3.9 g of KOH
(70 mmol) are added. The reaction mixture is refluxed for 3 hours. Acidifying the cooled reaction mixture with a concentrated aqueous HCl solution,
The precipitated material is filtered off: yield 9.0 g (95%).

4'-hydroxy-biphenyl 4-4-(9-decenyloxy) benzoate (sic) (D) CH ₂ Cl ₂ (pure) 200 ml of triethylamine 8.3 ml (60 mm
ol), 7.4 g of 4,4'-dihydroxybiphenyl (40 mmo
l) In solution at 20 ° C trimethylchlorosilane 7.5
ml (56 mmol) are added dropwise and the mixture is stirred for 1 hour. Then 8.3 g (30 mmol) of C, 6.2 g (30 mmol) of DCCI and 600 ml (5 mmol) of DMAP are added and the mixture is stirred for 24 hours. The precipitate formed is filtered off, the solvent is eliminated and the residue is recrystallized from ethanol which has been weakly acidified with HCl; yield 5.8 g (44%).

4 '-(1-methylheptyloxy) biphenyl R-
(+)-4--4- (9-decenyloxy) benzoate (as is) (E) D2.2 g (5 mmol) in 80 ml of pure tetrahydrofuran,
To a solution of 800 mg (5 mmol) of S-2-octanol and 1.4 g (5 mmol) of triphenylphosphine, at 0 ° C., 870 mg (5 mmol) of ethyl azodicarboxylate was added dropwise while stirring to remove water. Stir the mixture at room temperature for 48 hours. Then the solvent is eliminated and the residue is recrystallized from ethanol and purified by column chromatography; yield 1.45 g (52%); ▲ [α] ²⁵ _D ▼:
_{+1.2 (C = 0.012 / CHCl 3} ).

Biphenyl 2S, 3S-(+)-4--4- (9-decenyloxy) benzoyloxy-4 '-(2-chloro-3-
Methyl pentanoate (sic) (F) 2.2 g (5 mmol) of D, 750 mg (5 mmol) of 2S, 3S-2-chloro-3-methylpentanoic acid, and 100 mg (0.75 mmol) of dimethylaminopyridine (DMAP) At 0 ° C.,
1.3g of dicyclohexylcarbodiimide (DCCI) (5mmo
l) is added. The mixture is stirred for 24 hours at room temperature. The precipitate is filtered off with suction, the solvent is eliminated and the residue is purified by column chromatography; yield 1.35 g (47%); ▲ [α] ²⁵ _D ▼: +2.7 (C = 0.015)
/ CHCl _3).

The polyaddition of E and F with polyhydrogenmethylsiloxanes of various molecular weights is carried out according to general operating procedures.

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁶ , DB name) C08F 283/12 C09K 19/40

Claims (1)

(57) [Claims] (1) The following formula (I) [Wherein z is CH ₃ or formula (II) (CH ₂ ) _a (-B) _b -M ¹ , provided that at least two substituents z in the polymer are groups of formula (II). (−A ¹ ) _c (−M ² ) _d (−A ² ) _e (−M ³ ) _f (−A ³ )
_g is a group represented by R ¹ (II), n is 5 to 500, and B is a group represented by the following formula: (Wherein R ⁶ , R ⁷ and R ⁸ are the same or different and H, CH ₃ , OC
H ₃ , F, Cl or Br, in which case at least one group
R ⁶ , R ⁷ , or R ⁸ must be H. Next, X is H, F, Cl
Or R ⁹ is H or C ₁ -C ₁₀ alkyl)
Wherein R ¹ represents one or two non-adjacent —CH ₂ groups by —O—, —S—, —CO—, —CO—O
-, -O-CO- or -O-CO-O-, and also straight-chain or branched (asymmetric) having 1 to 16 carbon atoms which can be replaced by H by H. Alkyl with or without carbon atoms) or alkenyl with 2 to 16 carbon atoms, or also a radical of the following Wherein R ² , R ³ , R ⁴ , and R ⁵ are H, or one —CH ₂ — group can be replaced by —O—, —CO—O—, or —O—CO—. A mirror or branched alkyl having 1 to 16 carbon atoms, or an alkenyl having 2 to 16 carbon atoms, or R ² and R ³ or R ⁴ and R ⁵ together have 3 to 8 carbon atoms A is from 2 to 20, preferably from 6 to 12, and b, c, d, e, f
And g are 0 or 1 provided that e + f + g is 2 or 3, and A ¹ , A ² and A ³ are the same or different;
1,4-phenylene in which one or two H can be replaced by F, Cl, and / or CN, one or two H can be replaced by F, Cl,
Trans-1,4-cyclohexylene, pyrazine-2,5-diyl, which can be substituted by CN and / or CH ₃ ,
Pyridazine-3,6-diyl, pyridine-2,5-diyl, pyrimidine-2,5-diyl, (1,3,4) -thiadiazole-
2,5-diyl, 1,3-dioxane-2,5-diyl or 1,3-
A dithiane-2,5-diyl, M ² and M ³ are identical or different CO-O, O-CO, CO-S, a S-CO, CH ₂ -O or O-CH _2, M ¹ is Or CH ₂ —CH ₂ , and G represents one or two non-adjacent —CH ₂ groups by —O—, —S—, —O—CO, —CO—O—,
Linear or branched alkyl having 1 to 16 carbon atoms or alkenyl having 2 to 16 carbon atoms, which can also be substituted by -S-CO- or -CO-S-, but of the formula (II) Wherein b = 0 and R ₁ is not directly attached to a mesogenic group, or one or two
Excluding liquid crystalline polymers that are either chiral alkyls having an asymmetric carbon atom bridging through one atom or achiral alkyls having 1 to 16 carbon atoms]
Ferroelectric liquid crystalline polymer.